Seroprevalence of human granulocytic anaplasmosis in Berlin Brandenburg, Germany: an 8-year survey

ABSTRACTThis study investigated the seroprevalence of antibodies against Anaplasma phagocytophilum in Berlin/Brandenburg, north-eastern Germany. During 1994–2001, 422 sera from patients with proven tick-exposure (specimens with antibodies against Borrelia burgdorferi) were compared with 249 control sera. Using indirect fluorescent antibody testing, significantly more positive samples were detected among Borrelia antibody-positive specimens (4.5%, 95% CI 2.5–6.5%) than among controls (1.2%, 95% CI 0.5–1.9%; p < 0.05). While six (2.2%, 95%CI 1.3–3.1%) samples were positive among Borrelia antibody-positive sera between 1994 and 1997, 13 (8.7%, 95% CI 6.9–10.5%) were positive between 1998 and 2001 (p < 0.01), indicating an uneven annual seroprevalence.